The 55Zh6U Nebo-U is a Russian meter-band, three-coordinate radar for medium- and high-altitude air surveillance, target-coordinate reporting, and support to automated air-defense command systems. Developed by NNIIRT as a deep modernization of the earlier 55Zh6 Nebo, it uses a large cross-shaped phased-array antenna and has been documented in Russian service during the Russia-Ukraine war through reported Ukrainian strikes on Nebo-U radars in occupied Crimea.
Russian forces have fielded Nebo-U radars in occupied Crimea during the war; Ukrainian General Staff-sourced reporting documented strikes on a 55Zh6U Nebo-U near Yevpatoriia on February 12, 2026, and another Nebo-U at Feodosia in April 2026.
Role detailsThe 55Zh6U Nebo-U is a large transportable sensor for the air-defense radar layer, not a self-contained interceptor. Russian reference material describes it as a meter-band, three-coordinate station that can operate autonomously or feed automated air-defense command systems with range, azimuth, and height data.
Meter band / VHF.
Cross-shaped phased-array antenna with separate rangefinder and height-finder arrays mounted on three semitrailers.
The set includes an equipment cabin, diesel power station, and remote-control unit that can operate up to 1,000 m from the radar.
Ukraine-war reports treat Nebo-U as a Russian long-range surveillance and air-defense radar target in occupied Crimea.
Nebo-U should be separated from Nebo-SV, Nebo-SVU, Nebo-M, and Niobium-SV reports unless the source names 55Zh6U or Nebo-U directly.
Nebo-U sits in the Soviet/Russian Nebo meter-band radar family: a deep modernization of the original 55Zh6 Nebo, distinct from the more mobile ground-forces Nebo-SV/SVU branch and from later Nebo-UM/Niobium and Nebo-M systems.
| Variant | Configuration | Designation notes |
|---|---|---|
| 55Zh6 Nebo | Earlier three-coordinate VHF radar | The Great Russian Encyclopedia describes Nebo-U as a deep modernization of the earlier 55Zh6 Nebo radar. |
| 55Zh6UE Nebo-UE | Export designation | Open reference material uses Nebo-UE / 55Zh6UE for the export form of the Nebo-U radar. Sources: GlobalSecurity Nebo-U Profile |
| 55Zh6UM Nebo-UM / Niobium | Later modernization path | GlobalSecurity describes the 55Zh6UM / Niobium line as a later Nebo-family modernization, with development work launched from the Sky-U base in 2010. Sources: GlobalSecurity Nebo-U Profile |
| 55Zh6M Nebo-M | Later multi-band radar complex | Open family references distinguish Nebo-M as a later multi-band radar complex rather than a simple 55Zh6U variant. Sources: Radartutorial 55Zh6U Nebo-U Profile |
 | Ground-forces mobile Nebo branch | The Nebo family also includes the mobile ground-forces Nebo-SV branch; it is a related family member rather than the same radar. Sources: GlobalSecurity Nebo-U Profile |
 | Later mobile VHF derivative | The Nebo-SVU is a separate mobile derivative in the same VHF radar family and should not be collapsed with 55Zh6U Nebo-U conflict reporting. Sources: GlobalSecurity Nebo-U Profile |
 | Later ground-forces Niobium branch | Niobium-SV belongs to a later Nebo/Niobium development path; open sources distinguish it from the large Nebo-U radar. Sources: GlobalSecurity Nebo-U Profile |
Open reference material traces the 55Zh6U Nebo-U development program to NNIIRT work that began in 1986.
Sources: GlobalSecurity Nebo-U Profile
GlobalSecurity reports that the 55Zh6U radar was tested at Kapustin Yar in 1992.
Sources: GlobalSecurity Nebo-U Profile
The Great Russian Encyclopedia lists 1995 as the Nebo-U service-adoption year and says initial serial production began at NNIIRT.
Sources: Great Russian Encyclopedia Nebo-U Entry
The Great Russian Encyclopedia says serial production at Nizhny Novgorod Television Plant began in 2011.
Sources: Great Russian Encyclopedia Nebo-U Entry
Kyiv Post reported a Ukrainian military-intelligence claim and drone footage showing a strike on the antenna of a Russian 55Zh6U Nebo-U radar in occupied Crimea.
Sources: Kyiv Post Crimea Nebo-U Strike
Ukrainian Pravda, citing Ukraine's General Staff, reported that Ukrainian forces hit a Russian 55Zh6U Nebo-U radar near occupied Yevpatoriia in Crimea.
Sources: Ukrainian Pravda Yevpatoriia Nebo-U Strike
UNN and The New Voice of Ukraine reported a Ukrainian General Staff confirmation that Ukrainian forces struck a Nebo-U radar at occupied Feodosia in Crimea.
Sources: UNN Feodosia Nebo-U Strike, NV Feodosia Nebo-U Strike
